The large majority of about 50 pilot whales stranded across Farewell Spit near Nelson have returned to sea. 

DOC and Project Jonah crew have returned to the site of yesterday's stranding, helping cool the creatures in the rising sun. 

Some mammals appear to still be stuck on the high tide line, with only a small window of time to get them out to deeper water. 

Project Jonah Volunteer Manager Louisa Hawkes told Andrew Dickens they've had a tough night. 

She says that six whales died overnight, but 15 are still alive, and the rest of the pod appears to have swum off and stayed in deeper water. 

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